Incident Overview
On 12 August 2017, a Schleicher ASK 21 glider, registration I-NIBO, operated by Aero Club Adele Orsi, made an off-field landing approximately 1.2 km southwest of Stabio, Ticino, Switzerland. The two pilots, Italian nationals born in 1957 and 1958, had departed from Calcinate del Pesce aerodrome (LILC) in Italy at 13:57 local time for a local flight. The glider was seriously damaged; the pilot in the rear seat sustained a fracture of the last thoracic vertebra, while the front pilot was uninjured.
Flight History
The glider was towed aloft and released. The pilots alternated controls, flying north and east of the departure field for nearly two hours, reaching a maximum altitude of 1500 m. They then headed east, but south of Chiasso at about 1000 m, they turned west and could not find usable thermals. Realizing they could not glide back to LILC, they considered an off-field landing. At that point, they were already outside the cone of LILC.
The front pilot, Pilot A, took control. Southwest of Stabio, they spotted two fields suitable for landing at an altitude of about 600 m AMSL (245 m AGL). They misjudged the field elevation, believing it to be similar to LILC’s, estimating 400 m AGL. They spiraled over the fields, losing altitude, and chose a field south of an industrial complex, estimating its length at 200 m.
At about 450 m AMSL (95 m AGL), Pilot A overflew the field eastwards and began a 270-degree right turn approach. On final approach northbound at 110 km/h with a steep descent, he fully extended the airbrakes. The glider impacted the ground heavily about 90 m before the end of the field and stopped after 50 m.
Injuries and Damage
The impact forces seriously damaged the lower front fuselage and nose wheel. The structure deformation absorbed much of the energy. Both pilots were restrained by four-point harnesses and exited the aircraft unaided. Pilot B sustained a fracture of the last thoracic vertebra due to his seating position directly above the main gear. This was the first off-field landing for both pilots.
Aircraft Information
The Schleicher ASK 21 is a two-seat glider with a 17 m wingspan and a glide ratio of 33.5. It has a main gear under the wings and a fixed nose wheel. The recommended final approach speed is 90 km/h.
Meteorological Conditions
At the time, southern Ticino experienced weak to moderate foehn wind from the north. The sky was cloudless, visibility 40 km. Wind at the site was 30 degrees at 4 kt, gusts up to 15 kt. Temperature 26°C, dew point 7°C, QNH 1015 hPa.
Analysis
The investigation found no pre-existing technical defects that could have influenced or caused the accident. The pilots’ decision-making and judgment during the off-field landing were key factors, though no explicit causal conclusion is provided in the report.